are hermit crabs?
Have you ever eaten a crab? It's difficult to eat
a crab, you have to crack open its shell to eat it. Have
you ever eaten a prawn? A prawn has a long body is much
easier to eat..
The front part of a hermit crab (its pincers and walking legs) have
hard shells like a crab. But it has a long soft abdomen, like a
prawn which doesn't have a shell. To protect its abdomen, it has
to tuck it into an empty snail shell.
Hermit crabs belong to a group of animals called crustaceans. Other
crustaceans include crabs, shrimps and prawns.
A closer look at hermit crabs
at the shells around you and see what is living inside it! Do
this at a spot where there are likely to be many hermit crabs.
"See, almost every empty shell has a hermit crab in it! That's
why we should not take any shells home with us. Every empty shell
is a potential hermit crab home. Even a tiny broken shell or an
ugly shell covered with barnacles. One of the factors limiting
the population of hermit crabs is the availability of suitable
empty shells. So please don't take any shells away from our shores."
hermit crab has many hitch-hiking friends! "What
other animals can you see living with the hermit crab in its shell?"
- A hermit
crab home is a cosy and safe place for small animals.
airconditioning: the hermit crab keeps a constant flow of
left over food
from predators and drying out: hermit crabs scurry into hiding
places or bury themselves under sand.
crabs understood the concept of 'upgrading' long before other
Singaporeans! As a hermit crab grows bigger, it has to
find a bigger shell. Before switching shells, a hermit crab will
tentatively test out the new shell first, while holding on to
the old one. If the new one is not ideal, it instantly goes back
into the old shell.
crabs are important to the ecosystem
- Many animals
live together with a hermit crab. If you remove a hermit crab,
you also affect his many friends.
- Many animals
love to eat hermit crabs!
They are an important part of the ecosystem. Can
we think of some animals that might eat a hermit crab? Some
charismatic animals to highlight: shorebirds, crabs.
- Most hermit
crabs are scavengers and eat up dead animals on the shore. They
help quickly recycle dead things.
crabs and you
we keep hermit crabs as pets at home?
crabs sold as pets are usually taken from the wild.
die during the collection process, before they are even
many of those sold eventually die from neglect or ignorance
of proper care.
small animals live with hermit crabs. Removing wild hermit
crabs affects these small animals too.
crab myths to dispel
crabs belong in their shells! Please
don't try to pull hermit crabs out of their shells. There are
appendages at the end of the hermit crab's abdomen to hang on
tight to the shell. If you pull the hermit crab, you may rip out
their little appendages or tear their delicate abdomens.
- A hermit
crab does not necessarily always use the same kind of shell.
crabs never kill the original occupant of the shell. They
may, however, quarrel with each other over a desirable shell.
Finding hermit crabs: Almost every shore will have
some sort of hermit crab. A pile of small shells on a rock
at low tide are usually inhabited by tiny hermit crabs. During
the day, many are buried in the sand. Bigger ones may be found
Be gentle! Do not poke or prod or shake hermit crabs
to get them to come out.
How to get the hermit crab to come out? The
best way is to face the shell opening down and away from the
light and wait patiently. Another harmless way to get them
to come out is to pour plain water into the shell.
Remind visitors NOT to pull hermit crabs out of their shells.
They will tear the animal in half as it has tiny claws on
its butt to hang onto the shell.
Beware! Hermit crabs can pinch! Large hermit crabs
can give a good pinch. Don't let small children handle them.